Create a smooth, well rounded aircraft nose (with a low poly constraint)
I don't know whether this is lo-poly enough for you.. there's a similar number of edges around the cone, (quite hi-poly, in my book)



Assuming an even number of vertices in the circumference:


Cut off  the tip to your second line, select the perimeter of the hole
CtrlF Face menu > 'Grid Fill', adjust spans and offset.
with O Proportional Editing on,smooth, bring out the central vertex
In vertex mode, Vertex menu > 'Smooth vertices', on a larger region of the nose


This way, you might have to model the part with the Mirror modifier applied.. it is symmetrical, though, so you can slice it in half and stick it back.